Centrifugal casting apparatus for molding metal and other materials



July 16, 1929. w. A. |y|.l\RRn\1csTor-1y 1,721,115

CENTRIFUGAL CASTING APPARATUS FOR MO1'.1D]N 5Y METAL AND O'I'IERy MATERIALS Fired Feb. 1, 192e 2 sheets-sheet 2 Patented July 16, 1929.

UNITED STATES PATENT OFFICE.

WILLIAM ALFRED- HARRINGTON, or LEIGHHARDT, NEAR SYDNEY, NEW sou'rn f WALES, AUSTRALIA.

CENTRIFUGAL CASTING APPARATUS FOR HOLDING- METAL AND OTHER MATERIALS.

Application led February 1, 1928, Serial No.

This invention relates to an improved centrifugal apparatus adapted principally for casting molten metal, but usable also for molding cement and other plastic substances.

In molding or casting operations, it is customary to employ rotating molds and to utilize centrifugal force to evenly distribute molten metal throughout the interior of the mold for the formation of hollow castings of specially dense nature. Centrifugal molding machines of turret type are known, such machines comprising a turntable supporting a plurality of molds capable of being rotated and brought into register with a pourer. My invention provides a centrifugal molding apparatus of this type, but characterized by several novel and improved features which render it particularly efficient in expeditious handling of repetition work such as, for eX- ample, the casting 0f metal cylinders adapted to be subsequently cut and formed into piston rings, bearing bushes and other hollow articles. In the accompanying exemplary drawings Figure 1 is a view in elevation of the improved apparatus showing two of thevmold'- ing units.

Figure 2 is a plan view of the complete apparatus.

Figure 3 is a perspective view of the base frame and turntable of the apparatus.

Figure 4 is a sectional view centrally through the frame and turntable.

Figure 5 is a perspective view of one of the molding units.

Figure 6 is a sectional detail view of one of the molds.

The improved apparatus, as illustratedin these views, has a base member 2 stationarily supported upon legs 3. Said base member is of tubular construction and has three principal portions 4, 5 and 6. The lower external portion 4 is shaped for the attachment of the legs 3, and the portion 5 is formed as a flange to support a turntable block 7, while the portion 6 forms a bearing in which the turntable block is rotatably: fitted. The turntable block 7 has a flange 8 to bear upon the Hangs 5 of the base member. Said lange 8 has a series of notches 9 adapted when the turntable is rotated to successively align with a notch 10 in the iange 5. A. locking lever 11 is pivoted at 12 to one of the legs 3 and 1t 251,166, and in Australia February 24, 1927.

has one end 13 shaped to engage the registering notches 9, 10 whereby the turntable can be locked in various rotated positions. The outer end of the lever 11 is provided with a pedal 14 enabling foot pressure to be used to dlsengage the locking end of said lever from the notches. A spring 15 connected to the lever 11' and to a bracket 16 automatically forces the locking lever into the notches when same are brought into alignment.

The turntable block 7 of the apparatus has an axlal hole or bore 17 accommodating a vertical shaft 18 journaled in suitable thrust bearings 19. supports a driving disc or element 20, while its lower-end carries a pulley wheel 21 driven by a' belt from a suitable power unit. Other approved means may be employed'for rotat` 'lhe upper end of said shaft tured boss 25 receiving a pivot pin 26 Wherev on a carrier 27 is pivotally mounted. This carrier has two end bearings 28 and 29 wherein is journaled a horizontal mold rotating shaft 30. Mounted on the inner end of said shaft 30 is a friction wheel 31, preferably of libre, adapted to frictionally engage the upper surface of the driving disc 20 and be rotated thereby. The'friction wheel 31 is capable of adjustment upon a long keyway 32 in the shaft 30 whereby said friction wheel can be moved towards or away from the centre of the driving disc 20, thus varying the speed of rotation of said shaft without alteration of the speed of the driving disc.

Formed on the end bearing 28 of the carrier are two lugs 33 supporting a horizontal lead screw 34 .11aving right and left hand threads thereon., Nuts 35 and 36 are fitted on said lead screw and are connected to brake shoes 37 which are pivoted at their lower ends to the base portion of the carrier. The lead -screw 34 is rotated by hand through a loose handle 38 causing the nuts'35 and 36 to be moved either inwardly or outwardly to actubrake shoes. By rotating the handle in one direction, the brake shoes are forced into frictional engagement with a brake disc f 39 mounted on the shaft 30, thus stopping the Fitted to the outer end of the shaft 30 is a face plate 40 to which a mold 41 is secured by means of bolts- 42 passing through holes 43 in said face plate. The face plate can be used to -support molds of various diameters` and for this purpose it has a series of holes 43 formed at different radii from its cent-re. Alternatively, radial slots/may be provided in the face plate 1n lieu of said holes so that molds of various diameters may be secured thereto.

Fitted beneath the inner end of the carrier 27 is a compression spring 44 (see Figure 1) which exerts upward pressure on the carrier, normally tending to hold it in tilted position on the pivot 26 with its friction wheel 31 out of engagement with the driving disc 20. The carrier is adapted to be moved to driving position by means of a cam 45 mounted on a pin 46 whichl is supported in a boss 47 on the outer end of .the bracket 23. The cam contacts wit-h an adjustable screw 48 fitted to the un# dersurface ofthe carrier and provided with a lock-nut 49 whereby it can belocked in desired adjusted position. The purpose of said adjustment screw 48 is to enable any wear on the cam 45 to be conveniently provided for.

The cam 45 has a handle 50 whereby it can be conveniently l rotated. By forcing the handle 50 downwardly, the cam exerts upward pressure on the outer end of the carrier.

This action pivotally moves the carrier against the coiled spring 44, moving the -friction wheel 31 downwardly into contact with the driving disc'20 ,and thus causing the shaft 30 and the mold rto be rotated. By moving the cam handle 5 0 upwardlyg/the pressure of the cam on the screw 48 ,is relaxed, allowing the spring 44 to elevate the inner end of the carrier. The friction wheel 31 is thereby raised out of engagement with the driving disc, thus disconnecting the drive to the mold.

To prevent accidental engagement of the friction wheel 31 with the'driving disc a safety gravity catch 51 is pivoted to the 1nner end portion of the carrier, and is adapted to automatically fall to the position .shown in Figure 5, thus engaging the edgel of the bracket 23' and p'reventlng the inner end of the carrier being lowered.' The catch 51 is furnished with a handle 52 whereby it can be conveniently disengaged by the operator before he operates the cam lever 50 to move the friction wheel 31 into engagement with the` driving Vdisc 20.

The molds 41 are preferably of cylindrical shape, but may be of other shape if desired.

Each mold has a detachable end cap 53 provided with a bayonet coupling 54 whereby it' can be readily fitted to and detached from the mold. The outer end of vthe mold has a portion of reduced thickness providing an annular recess or pocket 55 when the end cap 53 is fitted. The purpose of the recess 55 is to form an end flange on the casting for chucking purposes during subsequent Inachining operations.

The turntable is adapted to be rotated to successively bring the molds into position in front of a stand 56 supporting a metal pourer 57.' This pourer is provided with a handle member 58 which is slidable in slots 59 in the upper end of the stand, thus enabling the pourer to be conveniently advanced into or Withdrawn from the mold.

A hood or shield 60 is slidably mounted on supports 61 on the stand 56 and is adapted to partially enclose the mold and the pourer as shown in Figure 1, thus intercepting any molten metal which may be flung by the mold during. pouring.

In the operation of the apparatus, molds of suitable size are secured to the face plates 40 and the cam handles 50 are actuated to tilt the carriers 27 and move the friction manually rotated by handles 62 on the carriers to bring one of the rotating molds into position opposite the stand 56 and the turntable is then locked in set position by the locking lever 11. The pourerl 57 is moved forwardly into the rotating mold by its handle 584, and the shield 60 is slidably' moved to the forward the pourer. Y

Molten metal from a ladle or the like is now vdelivered into the pourer 57 and discharged into the rotating mold wherein it is evenly distributed by centrifugal action l position to cover the mold and L throughout the body of the mold to form the hollow casting of desired thickness. The pourer 57 and the shield 60 are then withdrawn, enabling the turntable to vbe partially rotated to move the succeeding mold into position for casting. While each sucv cessive casting operation is in progress, the casting which has been completed just previously is Withdrawn from its mold by the operator who raises the cam handle 50 to disengage the friction wheel 31 from the driving disc 20. The safety catch 511s simultaneously set, thus preventing accidental re-engagement of the friction wheel 31.

The operator now stops the rotation 'ofthe mold by actuating the handle 38 to apply the brake and when the mold has 'ceased to rotate, the end cap 5 3 is removed. Tongs or like tools are inserted the hollow casting'and the latter" is Y withdrawn fromby a spray of water or cooling fluiddirected vthereon.v If desired, the cooling iiuid may containthe. coating mixture for the internal surface lof the mold, 'the mixture remaining .Y on the surface of the mold after evaporation of the cooling uid. i

The speed at which the molds are rotated will depend upon the sizes o'f the molds theA particular .metal or material being cast and.

.other conditions.- vOrdinarily, molds of small diameter will be rotated at higher speed than large molds. Consequently, the friction wheels 3l of units supporting small molds will be adjusted .furthest from the centre of the driving disc 20..

Vilhatl do claim is 15A' centrifugal apparatus of the turret type, comprising a driving element, a turntable, a series of bracket members carried byv said turntable, shafts supported from said brackets and arranged radially around the driving element, a mold at the outer end of each of said shafts, a pourer for fluid material under treatment, means for rotating the turntable to successively bring the molds into position to receive lmaterial from the pourer, a driving wheelon the inner end of each of said shafts to engage the said driving element whereby the molds arerotated, and means. for tilting each of said shafts whereby the 'driving wheels are disengaged from. the said driving element to disconnect the drive to each of the molds independently.

2. A centrifugal apparatus of the turret type, comprising a frame, a driving element, a turntable rotatably mounted on said frame, a series of bracket members supported from said turntable, carriers pivotally mounted on said brackets, shafts supported in said carriers, a mold at the outer end of each of said shafts, a driving wheel at the inner end of each shaft to engage the driving element whereby the molds are rotated, a pourer for fluid material under treatment, means for rotating theV turntable'to successively bring the molds into position to receive material from the pourer, and means for pivotally moving the carriers independently whereby the driving wheels on the shafts are dis engaged from the driving-element to stop the rotation of the molds.

A centrifugal `apparatus according to claim 2, wherein the carriers have springs tending to hold the driving wheels out of engagement with the driving element, and

wherein cam means are provided for pivot' ally moving the carriers to force the driving wheels into engagement with the dr1v1ng element.

. 4:. A centrifugal, apparatus according to claim 2, wherein brakingmeans are provided on each ofthe mold supportingicarr'iers for braking the rotation ofthe mold shafts independently-When the driving wheels have beenl disengaged fromthe .driving element.v

15.?AL .centrifugal apparatusy of the turret type comprising, a fra1ne,adriving disc supported on` said frame, means for rotating said disc, a turntable'rotatably mountedon Vsaid frame, means for locking vsaid turntable in set rotated position, aseries of brackets supported from the turntable, carriers pivotally mounted on said brackets, shafts supported in said carriers, a mold at the outer end of each of said shafts, a driving `wheel on the inner end of each of said shafts, means for pivotally mov'ingthe carriers to engage the driving wheels with the driving disc to rotate the molds, braking ymeans for stopping rotation of the molds when the driving wheels aredisengaged, a pourer for iiuid material under treatment, andmeans for rotating the turntable to successively bring the molds into position to receive 4material from the pourer.

6. In a centrifugal apparatus of the turret type, a frame, a turntable rotatable on said frame, a central driving disc, a series of brackets supported from said turntable, radially arranged shafts supported from said brackets, a .mold at Ithe end of each of said shafts, a member on each of said shafts engaging the driving disc whereby the molds` are rotated, means for delivering Huid material into the rotating molds, and means for independently disconnecting each of said mold shafts from the driving disc at will.

7. lin a centrifugal machine of the turret type, a driving element, a series of shafts each having at one end a mold and at the other end a driving wheel to engage the said driving elementwherebytheinold is rotated, carriers supporting said shafts, and means for tilting said carriers to disengage the driving wheels of the shafts from the said driving element.

8. In a-centrifugai machine ofthe turret type, a driving element, a series of Shafts arranged radially about said driving element and eachhaving a mold at one end and a type, comprising a frame, a driving element,

a turntable rotatably mounted on said frame,

a series of bracket members supported from.

said turntable, carriers pivotally mounted on said brackets, shafts supported in said carriers, a mold at the outer end of each of said shafts, a driving wheel at the inner end of llt? ' whereby it can be advanced into and Withdrawn from the rotating mold, and means for pivotally moving the carriers independently whereby the driving Wheels on the shafts are disengaged from the driving element to stop the rotation of the molds.

10. A centrifugal apparatus according to claim 2, wherein catch devices are provided to holdrthe carriers in tilted position with the driving wheels out of engagement with the drivingelement; and wherein braking means are provided on each of the mold supporting carriers for braking the rotation of the mold shafts independently when the driving Wheels have been disengaged from thel driving element.

11. A centrifugal apparatus of the turret type, comprising a fralne, a driving element, a turntable rotatably mounted on said frame, a series of bracket members supported from said turntable, carriers pivotally mounted on said brackets, shafts supported in said carriers, a mold at the outer end of each of said shafts, a 'driving Wheel at the inner end of each shaft to engage the driving element Whereby'themolds are rotated, said driving wheels being adjustable towards' or away from the center of the driving element Whereby the speed of rotation of the molds may be varied Without changing the speed of the driving element, a pourer' for' fluid material under treatment, means for rotatin the turntable to successively bring the mol s into position to receive material from the pourer, and means for pivotally moving the carriers independently whereby the driving Wheels on t e shafts are disengaged from the driv-y ing element to stop the rotation of the molds.

12. A centrifugal apparatus according to claim 2, in Which a safety catch is pivoted to each carrier for .engagement With the cor@ responding bracket to hold the carrier in tilted position with the associated driving wheel out of engagement With the driving elc- -n'ient 13. In a centrifugal machine of the turret type, a driving element, a series of shafts each having at one end a mold'and at the other end a driving wheel to engage the said driving element whereby the mold is rotated, carriers supporting said shafts, and a manually-rotated cam associated with. each carrier and operable at will to tilt the respective carrier and thereby disengage the driving wheel ot the carrier from the driving element.

14. In a centrifugal machine of the turret type, a driving element, a series of shafts each having at one en d a mold and at the other end a driving wheel to engage the said driving element whereby the mold is rotated, carriers supporting said shafts, means for tilting the carriers to disengage the driving wheels of the shafts from the driving element, and means individualto each carrier for holding it in tilted position. v

In testimony whereof I aiix my signature.

WlLLlAM ALFRED HARRINGTON. 

